/* ==========================================================================
   LXYang Research Group Website - Apple-inspired Design
   Modern, clean, and responsive styles
   ========================================================================== */

/* --------------------------------------------------------------------------
   1. CSS Variables & Design Tokens
   -------------------------------------------------------------------------- */
:root {
    /* Colors - Refined palette */
    --color-primary: #660874;
    --color-primary-dark: #4a0554;
    --color-primary-light: #8a1a96;
    --color-accent: #d93379;
    --color-accent-light: #f05a95;
    
    /* Neutral colors - Apple style */
    --color-background: #fafafa;
    --color-surface: rgba(255, 255, 255, 0.95);
    --color-surface-solid: #ffffff;
    --color-text: #1d1d1f;
    --color-text-secondary: #555555;
    --color-text-tertiary: #777777;
    --color-border: rgba(0, 0, 0, 0.08);
    --color-border-light: rgba(0, 0, 0, 0.04);
    
    /* Shadows - Subtle and refined */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.12);
    --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.16);
    
    /* Typography - System font stack for optimal rendering */
    --font-display: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-text: -apple-system, BlinkMacSystemFont, 'SF Pro Text', 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-mono: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, monospace;
    
    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --spacing-3xl: 4rem;
    --spacing-4xl: 6rem;
    
    /* Border radius */
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 18px;
    --radius-xl: 24px;
    --radius-full: 9999px;
    
    /* Transitions */
    --transition-fast: 200ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-base: 300ms cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);
    
    /* Container */
    --container-max: 1200px;
    --container-padding: 1.5rem;
}

/* --------------------------------------------------------------------------
   2. Background - Persistent across page loads
   -------------------------------------------------------------------------- */

/* Base background color */
html {
    background-color: #fafafa;
    min-height: 100%;
}

/* Background image layer - persistent using html pseudo-element */
html::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: url('images/bkg.png');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    background-attachment: fixed;
    opacity: 0.15;
    filter: blur(0.5px);
    z-index: -3;
    /* Hardware acceleration for smoother rendering */
    transform: translateZ(0);
    will-change: transform;
    /* Hint browser to cache this layer */
    backface-visibility: hidden;
}

/* White overlay layer */
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(180deg, 
        rgba(250, 250, 250, 0.95) 0%, 
        rgba(250, 250, 250, 0.9) 50%,
        rgba(250, 250, 250, 0.95) 100%);
    z-index: -2;
}

/* --------------------------------------------------------------------------
   3. Reset & Base Styles
   -------------------------------------------------------------------------- */
*, *::before, *::after {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
}

body {
    font-family: var(--font-text);
    font-size: 16px;
    line-height: 1.6;
    color: var(--color-text);
    background-color: transparent;
    min-height: 100vh;
    overflow-x: hidden;
}

img {
    max-width: 100%;
    height: auto;
    display: block;
}

a {
    color: var(--color-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
}

a:hover {
    color: var(--color-accent);
}

/* --------------------------------------------------------------------------
   4. Typography
   -------------------------------------------------------------------------- */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-display);
    font-weight: 600;
    line-height: 1.2;
    letter-spacing: -0.02em;
    color: var(--color-text);
}

h1 { font-size: clamp(2rem, 5vw, 3rem); }
h2 { font-size: clamp(1.5rem, 4vw, 2.25rem); }
h3 { font-size: clamp(1.25rem, 3vw, 1.75rem); }
h4 { font-size: clamp(1.125rem, 2.5vw, 1.5rem); }

p {
    margin-bottom: var(--spacing-md);
    color: var(--color-text-secondary);
}

/* --------------------------------------------------------------------------
   5. Navigation
   -------------------------------------------------------------------------- */
.navbar {
    position: sticky;
    top: 0;
    z-index: 1000;
    background: rgba(102, 8, 116, 0.98);
    backdrop-filter: blur(20px) saturate(180%);
    -webkit-backdrop-filter: blur(20px) saturate(180%);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
    transition: transform 0.3s ease, background 0.3s ease, box-shadow 0.3s ease;
}

.navbar.scrolled {
    background: rgba(102, 8, 116, 0.95);
    box-shadow: var(--shadow-md);
}

.navbar .container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: var(--spacing-lg) var(--container-padding) var(--spacing-lg) 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 3rem;
}

.navbar .container > .logo {
    flex-shrink: 0;
    align-self: center;
}

.navbar .container > .nav-content {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: var(--spacing-xs);
}

/* Nav header row for mobile layout */
.nav-header-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    width: 100%;
    gap: var(--spacing-sm);
}

.nav-titles {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}



.navbar .container > .nav-content .nav-title {
    text-align: left;
}

.group-logo-nav {
    height: 120px !important;
    width: auto !important;
    max-width: none !important;
    opacity: 0.95;
    transition: opacity var(--transition-fast);
    flex-shrink: 0;
    align-self: center;
    margin-left: 20px;
}

.group-logo-nav:hover {
    opacity: 1;
}

.navbar .container > .nav-content .nav-title h2 {
    font-size: 1.3rem;
    font-weight: 500;
    color: rgba(255, 255, 255, 0.7);
    margin: 0;
    letter-spacing: 0.02em;
    text-transform: uppercase;
}

.navbar .container > .nav-content .nav-subtitle {
    text-align: left;
}

.navbar .container > .nav-content .nav-subtitle p {
    font-size: 1.8rem;
    font-weight: 700;
    color: #ffffff;
    margin: 0;
    letter-spacing: -0.01em;
}

.navbar .container > .nav-content .nav-menu {
    justify-content: flex-start;
    margin-top: var(--spacing-lg);
}

.logo img {
    width: 110px;
    height: 110px;
    transition: transform var(--transition-fast);
}

.logo:hover img {
    transform: scale(1.05);
}

/* Navigation Menu */
.nav-menu {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    list-style: none;
    margin: 0;
    padding: 0;
}

.nav-menu a {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: 1rem;
    font-weight: 500;
    color: rgba(255, 255, 255, 0.9);
    letter-spacing: 0.02em;
    border-radius: var(--radius-full);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
    min-width: 3rem;
    height: 2.25rem;
}

.nav-text {
    display: inline-block;
    transition: all 0.4s cubic-bezier(0.68, -0.55, 0.265, 1.55);
    opacity: 1;
    transform: scale(1) rotate(0deg);
}

.nav-icon {
    position: absolute;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.4s cubic-bezier(0.68, -0.55, 0.265, 1.55);
    opacity: 0;
    transform: scale(0.5) rotate(-180deg);
    font-size: 1.25rem;
}

/* Hover状态：文字变图标 */
.nav-menu a:hover .nav-text {
    opacity: 0;
    transform: scale(0.5) rotate(180deg);
}

.nav-menu a:hover .nav-icon {
    opacity: 1;
    transform: scale(1) rotate(0deg);
}

/* Active状态：保持显示文字 */
.nav-menu a.active .nav-text {
    opacity: 1;
    transform: scale(1) rotate(0deg);
}

.nav-menu a.active .nav-icon {
    opacity: 0;
    transform: scale(0.5) rotate(-180deg);
}

.nav-menu a::before {
    content: '';
    position: absolute;
    top: 50%;
    left: 50%;
    width: 0;
    height: 0;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 50%;
    transform: translate(-50%, -50%);
    transition: width 0.4s ease, height 0.4s ease;
    z-index: -1;
}

.nav-menu a:hover::before,
.nav-menu a.active::before {
    width: 120%;
    height: 200%;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: #ffffff;
    transform: translateY(-2px);
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: 4px;
    left: 50%;
    width: 0;
    height: 2px;
    background: var(--color-accent);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    transform: translateX(-50%);
}

.nav-menu a:hover::after,
.nav-menu a.active::after {
    width: 40%;
}

/* Mobile Menu Toggle */
.menu-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    width: 44px;
    height: 44px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm);
    gap: 5px;
}

.menu-toggle span {
    display: block;
    width: 22px;
    height: 2px;
    background: #ffffff;
    border-radius: 2px;
    transition: all var(--transition-fast);
}

.menu-toggle.active span:nth-child(1) {
    transform: rotate(45deg) translate(5px, 5px);
}

.menu-toggle.active span:nth-child(2) {
    opacity: 0;
}

.menu-toggle.active span:nth-child(3) {
    transform: rotate(-45deg) translate(5px, -5px);
}

/* --------------------------------------------------------------------------
   6. Main Content Containers
   -------------------------------------------------------------------------- */
.main-container {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: var(--spacing-3xl) var(--container-padding);
}

.section-header {
    text-align: center;
    margin-bottom: var(--spacing-3xl);
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.section-header h1 {
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
}

.section-header p {
    font-size: 1.125rem;
    color: var(--color-text-secondary);
}

/* --------------------------------------------------------------------------
   7. Research Carousel (Homepage) - Redesigned
   -------------------------------------------------------------------------- */
.research-carousel {
    max-width: var(--container-max);
    margin: var(--spacing-3xl) auto;
    padding: 0 var(--container-padding);
    perspective: 1000px;
}

.carousel-container {
    position: relative;
    overflow: hidden;
    border-radius: var(--radius-lg);
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.15);
}

.carousel-track {
    display: flex;
    transition: transform 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

.carousel-item {
    flex: 0 0 100%;
    padding: var(--spacing-2xl);
    background: linear-gradient(135deg, var(--color-surface) 0%, rgba(255,255,255,0.9) 100%);
    box-shadow: var(--shadow-lg);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border: 1px solid var(--color-border);
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
    transform-style: preserve-3d;
}

.carousel-item h3 {
    font-size: clamp(1.25rem, 3vw, 1.75rem);
    color: var(--color-text);
    line-height: 1.3;
    margin: 0;
}

.carousel-item .meta {
    font-size: 0.9375rem;
    color: var(--color-primary);
    font-weight: 500;
    letter-spacing: 0.01em;
    margin: 0;
}

.carousel-item .content {
    flex: 1;
}

.content-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-2xl);
    align-items: center;
}

.carousel-item .abstract {
    font-size: 1rem;
    line-height: 1.7;
    color: var(--color-text-secondary);
    text-align: justify;
}

.carousel-item .img {
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-md);
}

.carousel-item .img img {
    width: 100%;
    height: auto;
    max-height: 280px;
    object-fit: contain;
    transition: transform var(--transition-slow);
}

.carousel-item:hover .img img {
    transform: scale(1.02);
}

.carousel-item .cta {
    align-self: flex-start;
    margin-top: 0;
}

.cta {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-md) var(--spacing-xl);
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-light));
    color: #ffffff;
    font-weight: 500;
    font-size: 0.9375rem;
    border-radius: var(--radius-full);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 4px 14px rgba(102, 8, 116, 0.3);
    position: relative;
    overflow: hidden;
}

.cta::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
    transition: left 0.5s ease;
}

.cta:hover::before {
    left: 100%;
}

.cta:hover {
    background: linear-gradient(135deg, var(--color-primary-dark), var(--color-primary));
    transform: translateY(-3px) scale(1.02);
    box-shadow: 0 8px 25px rgba(102, 8, 116, 0.4);
    color: #ffffff;
}

.cta::after {
    content: '→';
    transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.cta:hover::after {
    transform: translateX(6px);
}

/* Carousel Controls - Outside the card */
.carousel-controls {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-xl);
    padding: var(--spacing-md);
}

.carousel-controls button {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    border: none;
    background: var(--color-surface-solid);
    color: var(--color-text);
    font-size: 1.25rem;
    cursor: pointer;
    transition: all var(--transition-fast);
    box-shadow: var(--shadow-md);
    display: flex;
    align-items: center;
    justify-content: center;
}

.carousel-controls button:hover {
    background: var(--color-primary);
    color: #ffffff;
    transform: scale(1.1);
}

.indicators {
    display: flex;
    gap: var(--spacing-sm);
}

.indicators span {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    background: var(--color-border);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.indicators span.active {
    background: var(--color-primary);
    transform: scale(1.2);
}

.indicators span:hover {
    background: var(--color-accent);
}

/* --------------------------------------------------------------------------
   8. Research Section
   -------------------------------------------------------------------------- */
.research-section {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: var(--spacing-3xl) var(--container-padding);
}

.research-header {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    padding: var(--spacing-2xl);
    margin-bottom: var(--spacing-2xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--color-border);
}

.research-title {
    font-size: 2rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
}

.research-content {
    font-size: 1.0625rem;
    line-height: 1.7;
    color: var(--color-text-secondary);
    text-align: justify;
}

.research-category {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    padding: var(--spacing-2xl);
    margin-bottom: var(--spacing-2xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--color-border);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.research-category:hover {
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.12);
    transform: translateY(-8px);
}

.research-category::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(102, 8, 116, 0.03), transparent);
    transition: left 0.6s ease;
}

.research-category:hover::before {
    left: 100%;
}

.category-header {
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--color-border);
}

.category-title {
    font-size: 1.5rem;
    color: var(--color-primary);
    font-weight: 600;
}

.research-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-xl);
}

.research-grid-two-col {
    grid-template-columns: repeat(2, 1fr);
}

.research-card {
    background: var(--color-surface-solid);
    border-radius: var(--radius-md);
    overflow: hidden;
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    border: 1px solid var(--color-border-light);
    position: relative;
}

.research-card:hover {
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.12);
    transform: translateY(-8px);
}

.research-card::after {
    content: '';
    position: absolute;
    inset: -2px;
    background: linear-gradient(45deg, var(--color-primary), var(--color-accent));
    border-radius: inherit;
    opacity: 0;
    z-index: -1;
    filter: blur(8px);
    transition: opacity 0.3s ease;
}

.research-card:hover::after {
    opacity: 0.1;
}

.figure-image {
    width: 100%;
    height: auto;
    max-height: 280px;
    object-fit: contain;
    transition: transform var(--transition-slow);
    background: var(--color-background);
}

.research-card:hover .figure-image {
    transform: scale(1.03);
}

.card-content {
    padding: var(--spacing-lg);
}

.card-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--spacing-md);
    line-height: 1.4;
}

.publication-list {
    list-style: none;
    padding: 0;
    margin: 0;
}

.publication-item {
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    padding: var(--spacing-sm) 0;
    padding-left: var(--spacing-md);
    position: relative;
    border-bottom: 1px solid var(--color-border-light);
}

.publication-item:last-child {
    border-bottom: none;
}

.publication-item::before {
    content: '›';
    position: absolute;
    left: 0;
    color: var(--color-primary);
    font-weight: 600;
}

/* --------------------------------------------------------------------------
   9. Members Section
   -------------------------------------------------------------------------- */
.members-content-tag {
    font-size: 1.75rem;
    font-weight: 600;
    color: var(--color-primary);
    margin: var(--spacing-2xl) 0 var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--color-border);
}

.members-content-box {
    display: grid;
    grid-template-columns: 200px 1fr;
    gap: var(--spacing-2xl);
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    padding: var(--spacing-2xl);
    margin-bottom: var(--spacing-xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--color-border);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.members-content-box:hover {
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.12);
    transform: translateY(-4px);
}

.members-content-box::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 4px;
    height: 100%;
    background: linear-gradient(180deg, var(--color-primary), var(--color-accent));
    opacity: 0;
    transition: opacity 0.3s ease;
}

.members-content-box:hover::before {
    opacity: 1;
}

.members-content-image {
    border-radius: var(--radius-md);
    overflow: hidden;
    aspect-ratio: 3/4;
}

.members-content-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-slow);
}

.members-content-box:hover .members-content-image img {
    transform: scale(1.03);
}

.member-content-info {
    display: flex;
    flex-direction: column;
    justify-content: center;
}

.members-content-principle {
    margin-bottom: var(--spacing-md);
}

.members-content-principle b {
    font-size: 1.375rem;
    color: var(--color-primary);
    display: block;
    margin-bottom: var(--spacing-xs);
}

.members-content-principle p {
    font-size: 0.9375rem;
    color: var(--color-text-secondary);
    margin: 0;
    line-height: 1.6;
}

.members-content-context {
    font-size: 1rem;
    line-height: 1.7;
    color: var(--color-text-secondary);
    text-align: justify;
}

/* Alumni Section */
.alumni-section {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    padding: var(--spacing-2xl);
    margin-top: var(--spacing-3xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--color-border);
}

.section-title {
    font-size: 1.5rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-md);
    border-bottom: 2px solid var(--color-border);
}

.alumni-list {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.alumni-item {
    background: var(--color-surface-solid);
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
    border: 1px solid var(--color-border-light);
    transition: all var(--transition-fast);
}

.alumni-item:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.alumni-name {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--color-text);
    margin-bottom: var(--spacing-xs);
}

.alumni-period {
    font-size: 0.8125rem;
    color: var(--color-accent);
    font-weight: 500;
    margin-bottom: var(--spacing-sm);
}

.alumni-detail {
    padding-top: var(--spacing-sm);
    border-top: 1px solid var(--color-border-light);
}

.alumni-company {
    font-size: 0.9375rem;
    color: var(--color-text-secondary);
    font-weight: 500;
}

.alumni-position {
    font-size: 0.8125rem;
    color: var(--color-text-tertiary);
    margin-top: var(--spacing-xs);
}

/* --------------------------------------------------------------------------
   10. Tech Section
   -------------------------------------------------------------------------- */
#techniques-content {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: var(--spacing-3xl) var(--container-padding);
}

.tech-grid {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.tech-card {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-md);
    border: 1px solid var(--color-border);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
}

.tech-card:hover {
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.12);
    transform: translateY(-8px);
}

.tech-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.1), transparent);
    transition: left 0.6s ease;
    pointer-events: none;
}

.tech-card:hover::before {
    left: 100%;
}

.tech-header {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
    padding: var(--spacing-xl) var(--spacing-2xl);
    color: #ffffff;
}

.tech-acronym {
    font-size: 2rem;
    font-weight: 700;
    letter-spacing: 0.05em;
    display: block;
    margin-bottom: var(--spacing-xs);
}

.tech-fullname {
    font-size: 1.125rem;
    font-weight: 400;
    opacity: 0.9;
    letter-spacing: 0.02em;
}

.tech-body {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-2xl);
    padding: var(--spacing-2xl);
    align-items: center;
}

.tech-image-wrapper {
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.tech-image {
    width: 100%;
    height: auto;
    max-height: 320px;
    object-fit: contain;
    transition: transform var(--transition-slow);
    background: var(--color-background);
}

.tech-card:hover .tech-image {
    transform: scale(1.02);
}

.tech-description {
    font-size: 1rem;
    line-height: 1.7;
    color: var(--color-text-secondary);
    text-align: justify;
}

/* --------------------------------------------------------------------------
   11. Publications Section
   -------------------------------------------------------------------------- */
#publications-content {
    max-width: var(--container-max);
    margin: 0 auto;
}

.pub-nav {
    position: sticky;
    top: 195px;
    z-index: 100;
    background: rgba(102, 8, 116, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-radius: var(--radius-full);
    margin: var(--spacing-lg) var(--container-padding) var(--spacing-xl);
    padding: var(--spacing-sm);
    box-shadow: var(--shadow-lg);
    transition: top 0.3s ease;
}

.pub-nav.nav-hidden {
    top: 5px;
}

.year-links {
    display: flex;
    gap: var(--spacing-xs);
    overflow-x: auto;
    padding: var(--spacing-xs);
    scrollbar-width: none;
    -ms-overflow-style: none;
}

.year-links::-webkit-scrollbar {
    display: none;
}

.year-link {
    display: block;
    padding: var(--spacing-sm) var(--spacing-md);
    font-size: 0.9375rem;
    font-weight: 500;
    color: rgba(255, 255, 255, 0.8);
    border-radius: var(--radius-full);
    transition: all var(--transition-fast);
    white-space: nowrap;
}

.year-link:hover {
    color: #ffffff;
    background: rgba(255, 255, 255, 0.15);
}

.year-link.active {
    color: #ffffff;
    background: rgba(255, 255, 255, 0.25);
}

.pub-year {
    padding: var(--spacing-xl) var(--container-padding);
    scroll-margin-top: 215px;
}

.year-title {
    font-size: 2rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-xl);
    padding-bottom: var(--spacing-md);
    border-bottom: 3px solid var(--color-primary);
}

.pub-list {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
}

.pub-item {
    background: var(--color-surface);
    border-radius: var(--radius-md);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--color-border);
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.pub-item:hover {
    box-shadow: 0 12px 24px rgba(0, 0, 0, 0.1);
    transform: translateX(8px);
}

.pub-item::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    width: 4px;
    height: 100%;
    background: linear-gradient(180deg, var(--color-primary), var(--color-accent));
    opacity: 0;
    transition: opacity 0.3s ease;
}

.pub-item:hover::before {
    opacity: 1;
}

.pub-header {
    display: flex;
    flex-wrap: wrap;
    align-items: baseline;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-sm);
}

.pub-num {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-text-tertiary);
}

.pub-title {
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--color-text);
    line-height: 1.4;
    margin-bottom: var(--spacing-sm);
}

.pub-link {
    color: var(--color-primary);
    transition: color var(--transition-fast);
}

.pub-link:hover {
    color: var(--color-accent);
}

.pub-authors {
    font-size: 0.9375rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-sm);
    line-height: 1.5;
}

.highlight {
    color: var(--color-primary);
    font-weight: 600;
}

.pub-meta {
    display: flex;
    gap: var(--spacing-sm);
    font-size: 0.9375rem;
    color: var(--color-text-tertiary);
}

.journal {
    font-style: italic;
    color: var(--color-text-secondary);
}

/* --------------------------------------------------------------------------
   12. News Section
   -------------------------------------------------------------------------- */
#news-content {
    max-width: var(--container-max);
    margin: 0 auto;
    padding: var(--spacing-3xl) var(--container-padding);
}

.news-grid {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
}

.news-card {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    padding: var(--spacing-2xl);
    box-shadow: var(--shadow-md);
    border: 1px solid var(--color-border);
    transition: all 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    position: relative;
    overflow: hidden;
}

.news-card:hover {
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.12);
    transform: translateY(-6px);
}

.news-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: -100%;
    width: 100%;
    height: 100%;
    background: linear-gradient(90deg, transparent, rgba(102, 8, 116, 0.02), transparent);
    transition: left 0.6s ease;
}

.news-card:hover::before {
    left: 100%;
}

.news-header {
    margin-bottom: var(--spacing-lg);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--color-border);
}

.news-date {
    font-size: 0.875rem;
    font-weight: 600;
    color: var(--color-accent);
    letter-spacing: 0.02em;
    text-transform: uppercase;
}

.news-summary {
    font-size: 1rem;
    line-height: 1.7;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-lg);
}

.news-summary a {
    color: var(--color-primary);
    font-weight: 500;
    border-bottom: 1px solid transparent;
    transition: all var(--transition-fast);
}

.news-summary a:hover {
    border-bottom-color: var(--color-accent);
}

.news-figure {
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow-sm);
}

.news-image {
    width: 100%;
    height: auto;
    max-height: 500px;
    object-fit: contain;
}

/* --------------------------------------------------------------------------
   13. Footer
   -------------------------------------------------------------------------- */
.footer {
    background: linear-gradient(135deg, var(--color-primary-dark) 0%, var(--color-primary) 100%);
    color: rgba(255, 255, 255, 0.9);
    padding: var(--spacing-3xl) var(--container-padding) var(--spacing-lg);
    margin-top: var(--spacing-4xl);
    position: relative;
    overflow: hidden;
}

.footer::before {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.03) 1px, transparent 1px);
    background-size: 30px 30px;
    opacity: 0.5;
    pointer-events: none;
}

.footer-content {
    max-width: var(--container-max);
    margin: 0 auto;
}

.footer-section {
    margin-bottom: var(--spacing-2xl);
}

.footer-title {
    font-size: 1.25rem;
    font-weight: 600;
    color: #ffffff;
    margin-bottom: var(--spacing-lg);
    position: relative;
    padding-left: var(--spacing-md);
}

.footer-title::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 4px;
    height: 24px;
    background: var(--color-accent);
    border-radius: 2px;
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: var(--spacing-md);
    transition: transform var(--transition-fast);
}

.contact-item:hover {
    transform: translateX(4px);
}

.icon {
    flex-shrink: 0;
    fill: rgba(255, 255, 255, 0.7);
    transition: fill var(--transition-fast);
}

.contact-item:hover .icon {
    fill: #ffffff;
}

.address p {
    margin: 0;
    font-size: 0.9375rem;
    line-height: 1.6;
    color: rgba(255, 255, 255, 0.8);
}

.email, .tel {
    color: rgba(255, 255, 255, 0.9);
    font-size: 0.9375rem;
    transition: color var(--transition-fast);
}

.email:hover, .tel:hover {
    color: #ffffff;
}

.footer-divider {
    height: 1px;
    background: rgba(255, 255, 255, 0.15);
    margin: var(--spacing-xl) 0;
}

.copyright {
    text-align: center;
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.6);
    padding-top: var(--spacing-lg);
}

/* --------------------------------------------------------------------------
   14. Responsive Design
   -------------------------------------------------------------------------- */
@media (max-width: 1024px) {
    :root {
        --container-padding: 1rem;
    }
    
    .navbar .container {
        flex-wrap: wrap;
        justify-content: center;
        gap: var(--spacing-sm);
        padding: var(--spacing-md) var(--container-padding) var(--spacing-sm) 0.75rem;
    }
    
    .navbar .container > .logo {
        flex-shrink: 0;
        align-self: center;
    }
    
    .navbar .container > .nav-content {
        flex: 1;
        align-items: center;
        gap: var(--spacing-xs);
    }
    
    .navbar .container > .nav-content .nav-title h2 {
        font-size: 1.1rem;
    }
    
    .group-logo-nav {
        height: 85px;
        margin-left: 15px;
    }
    
    .navbar .container > .nav-content .nav-subtitle p {
        font-size: 1.5rem;
    }
    
    .navbar .container > .nav-content .nav-menu {
        flex: 1 0 100%;
        justify-content: center;
        margin-top: var(--spacing-xs);
    }
    
    .nav-menu {
        gap: var(--spacing-xs);
    }
    
    .nav-menu a {
        padding: var(--spacing-sm) 0.75rem;
        font-size: 0.95rem;
    }
    
    .content-row {
        gap: var(--spacing-lg);
    }
    
    .members-content-box {
        gap: var(--spacing-lg);
    }
    
    .tech-body {
        gap: var(--spacing-lg);
    }
}

@media (max-width: 768px) {
    /* Mobile Navigation */
    .navbar .container {
        display: grid;
        grid-template-columns: auto 1fr auto auto;
        grid-template-rows: auto;
        justify-content: space-between;
        padding: var(--spacing-sm) var(--container-padding) var(--spacing-sm) 0.5rem;
        gap: 0 var(--spacing-xs);
    }
    
    .navbar .container > .logo {
        grid-row: 1;
        grid-column: 1;
        align-self: center;
    }
    
    .navbar .container > .nav-content {
        grid-row: 1;
        grid-column: 2;
        align-self: center;
        align-items: flex-start;
        gap: 0;
        min-width: 0;
    }
    
    .navbar .container > .group-logo-nav {
        grid-row: 1;
        grid-column: 3;
        align-self: center;
        height: 48px !important;
        width: auto !important;
        max-width: none !important;
        margin-left: 0;
    }
    
    .navbar .container > .menu-toggle {
        grid-row: 1;
        grid-column: 4;
        align-self: center;
    }
    
    .navbar .container > .nav-content .nav-menu {
        display: none;
    }
    
    /* 侧滑菜单激活时显示 */
    .nav-menu.active {
        display: flex !important;
    }
    
    .navbar .container > .nav-content .nav-title,
    .navbar .container > .nav-content .nav-subtitle {
        display: block;
    }
    
    /* Mobile nav header row */
    .nav-header-row {
        flex-direction: column;
        align-items: flex-start;
        justify-content: center;
        gap: 0;
    }
    
    .nav-titles {
        flex: 1;
        min-width: 0;
    }
    
    .navbar .container > .nav-content .nav-title h2 {
        font-size: 0.6rem;
        line-height: 1.2;
    }
    
    .navbar .container > .nav-content .nav-subtitle p {
        font-size: 0.85rem;
        line-height: 1.2;
    }
    
    .navbar .container > .nav-content .nav-menu {
        margin-top: var(--spacing-sm);
    }
    
    .nav-menu a {
        padding: var(--spacing-xs) var(--spacing-sm);
        font-size: 0.9rem;
    }
    
    .menu-toggle {
        display: flex;
    }
    
    .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 80%;
        max-width: 300px;
        height: 100vh;
        background: rgba(102, 8, 116, 0.98);
        backdrop-filter: blur(20px);
        flex-direction: column;
        padding: 100px var(--spacing-xl) var(--spacing-xl);
        transition: right var(--transition-base);
        gap: var(--spacing-xs);
    }
    
    .nav-menu.active {
        right: 0;
    }
    
    .nav-menu a {
        padding: var(--spacing-md) var(--spacing-lg);
        font-size: 1rem;
        width: 100%;
        text-align: center;
        flex-direction: row;
        justify-content: flex-start;
        gap: var(--spacing-md);
        height: auto;
    }
    
    /* 移动端：文字和图标并排显示 */
    .nav-menu a .nav-text,
    .nav-menu a.active .nav-text {
        position: relative;
        opacity: 1;
        transform: none;
        display: inline-block;
    }
    
    .nav-menu a .nav-icon,
    .nav-menu a.active .nav-icon {
        position: relative;
        opacity: 1;
        transform: none;
        display: inline-flex;
        font-size: 1.25rem;
    }
    
    /* 移动端hover不切换 */
    .nav-menu a:hover .nav-text {
        opacity: 1;
        transform: none;
    }
    
    .nav-menu a:hover .nav-icon {
        opacity: 1;
        transform: none;
    }
    
    body.menu-open {
        overflow: hidden;
    }
    
    body.menu-open::before {
        content: '';
        position: fixed;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
        background: rgba(0, 0, 0, 0.5);
        z-index: 999;
    }
    
    /* Layout adjustments */
    .logo img {
        width: 80px;
        height: 80px;
    }
    
    /* Carousel - Mobile */
    .carousel-item {
        padding: var(--spacing-xl);
    }
    
    .content-row {
        grid-template-columns: 1fr;
    }
    
    .carousel-item .img {
        order: -1;
    }
    
    .carousel-item .img img {
        max-height: 200px;
    }
    
    .carousel-controls {
        margin-top: var(--spacing-lg);
    }
    
    /* Members */
    .members-content-box {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .members-content-image {
        max-width: 200px;
        margin: 0 auto;
    }
    
    /* Tech */
    .tech-body {
        grid-template-columns: 1fr;
    }
    
    .tech-image {
        max-height: 250px;
    }
    
    /* Publications nav */
    .pub-nav {
        top: 120px;
    }
    
    .pub-nav.nav-hidden {
        top: 5px;
    }
    
    .pub-year {
        scroll-margin-top: 140px;
    }
    
    /* News */
    .news-image {
        max-height: 350px;
    }
}

@media (max-width: 480px) {
    :root {
        --container-padding: 0.75rem;
    }
    
    .navbar .container {
        padding: var(--spacing-sm) var(--container-padding) var(--spacing-xs) 0.4rem;
        flex-wrap: wrap;
        justify-content: center;
        gap: var(--spacing-xs);
    }
    
    .navbar .container > .nav-content .nav-title h2 {
        font-size: 0.55rem;
    }
    
    .navbar .container > .nav-content .nav-subtitle p {
        font-size: 0.75rem;
    }
    
    .navbar .container > .group-logo-nav {
        height: 42px !important;
        width: auto !important;
        max-width: none !important;
    }
    
    .logo img {
        width: 70px;
        height: 70px;
    }
    
    .nav-header-row {
        gap: var(--spacing-xs);
    }
    
    .navbar .container > .nav-menu {
        flex: 1 0 100%;
        justify-content: center;
        margin-top: var(--spacing-xs);
    }
    
    .carousel-item {
        padding: var(--spacing-lg);
        gap: var(--spacing-md);
    }
    
    .carousel-item h3 {
        font-size: 1.125rem;
    }
    
    .carousel-controls {
        gap: var(--spacing-md);
    }
    
    .carousel-controls button {
        width: 40px;
        height: 40px;
    }
    
    .indicators span {
        width: 10px;
        height: 10px;
    }
    
    .research-header,
    .research-category,
    .members-content-box,
    .tech-card,
    .news-card {
        padding: var(--spacing-lg);
    }
    
    .alumni-list {
        grid-template-columns: 1fr;
    }
    
    /* 手机端：两列grid也改为单列 */
    .research-grid-two-col {
        grid-template-columns: 1fr;
    }
    
    .year-link {
        padding: var(--spacing-xs) var(--spacing-sm);
        font-size: 0.875rem;
    }
    
    .news-image {
        max-height: 280px;
    }
    
    .footer {
        padding: var(--spacing-2xl) var(--container-padding) var(--spacing-lg);
    }
}

/* Landscape mobile */
@media (max-width: 768px) and (orientation: landscape) {
    .nav-menu {
        padding-top: 80px;
    }
    
    .carousel-container {
        min-height: 400px;
    }
    
    .content-row {
        grid-template-columns: 1fr 1fr;
    }
    
    .carousel-item .img img {
        max-height: 150px;
    }
}

/* --------------------------------------------------------------------------
   15. Print Styles
   -------------------------------------------------------------------------- */
@media print {
    .navbar,
    .carousel-controls,
    .menu-toggle {
        display: none !important;
    }
    
    html::before,
    body::before {
        display: none;
    }
    
    body {
        background: white;
        color: black;
    }
    
    .research-carousel,
    .research-category,
    .members-content-box,
    .tech-card,
    .news-card,
    .pub-item {
        break-inside: avoid;
        box-shadow: none;
        border: 1px solid #ddd;
    }
}

/* --------------------------------------------------------------------------
   16. Accessibility
   -------------------------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
        scroll-behavior: auto !important;
    }
    
    .page-wrapper {
        animation: none;
    }
    
    .reveal-once,
    .reveal-left-once,
    .reveal-right-once,
    .reveal-scale-once {
        opacity: 1 !important;
        transform: none !important;
    }
}

/* Focus styles for keyboard navigation */
:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --color-border: rgba(0, 0, 0, 0.3);
        --shadow-sm: none;
        --shadow-md: none;
        --shadow-lg: none;
    }
}